1. Field of the Invention
This invention relates generally to dry material applicators suitable for airborne distribution of granular materials such as fertilizers, insecticides and fungicides, and more particularly, relates to a self-propelled centrifugal applicating device to be carried by an aircraft to apply the granular chemical materials by utilizing a pair of synchronized, air rotatable, star wheel spreaders.
2. Discussion of the Prior Art
There are numerous known applicator devices which are available for applying liquid and granular agricultural materials, such as herbicides, insecticides, fungicides, plant growth regulators and fertilizers by utilizing aircraft and other suitable agricultural material spreading equipment. Most of the prior art material spreaders were developed for use with liquid chemicals, and not too much prior work has been directed to the field of dry material applicators suitable for use with aircraft dispensing equipment.
In spraying dry or granular materials upon fields by employing aircraft, it is important that the product to be spread be uniform both in dimensions and in density to accomplish the best results, that is, the most uniform application pattern. So far as is known to the applicant, centrifugal applicating devices for dry materials have not heretofore been very widely employed, primarily due to the fact that such applicators inherently create turbulence in the sprayed product. Because of the turbulence, the prior available equipment could not develop maximum velocity in the dispersed particles. This then resulted in a random application of the dry agricultural materials, rather than in a controlled spray pattern. Cyclone type seeders are typical of the prior art dry material applicators. These devices usually function as three hundred and sixty degree applicators and all materials fed to the rotator were dispensed in turbulence due to the action of the rotating elements. Further, the known types of centrifugal prior art spreaders all had to be either manually turned or motor operated and no currently available self-propelled type of centrifugal spreader is known to the present applicant.